A fuel system, including fuel tanks, vapor lines, and other associated components of a motor vehicle may experience cracks, holes and fissures for various reasons. For example, roadway debris, such as rocks, may hit the fuel tank when the vehicle is traveling. As another example, normal wear and tear caused, in part, by the caustic effects of gasoline may lead to mechanical degradation of the fuel system. In some cases, the degradation may be very small, and, thus, difficult to detect and locate to enable repairs to be made.
One approach to detect fuel fluid and/or vapor leaks is to generate and deliver a visible vapor, such as a perceptible smoke, to a closed fluid system and inspecting the system for any vapor escaping therefrom. As such, the visible vapor may be delivered to a fuel tank via a fuel tank filler pipe in order to pressurize the fuel tank to be tested for leaks. However, in vehicles with a capless fuel tank filler pipe, it may be difficult to reliably couple a pressure source to the throat of the filler pipe. Moreover, it may be difficult to adequately maintain the pressure in the tank to enable a pressure test to be completed if a seal between the filler pipe and the pressure source is not secure. Adaptors may be used to couple the pressure source to the capless fuel tank filler pipe of the fuel tank of a motor vehicle. An example adaptor is described by McCollom et al. in US 2014/0159360, wherein the adaptor comprises of a hollow flow body to create a continuous flow path between the pressure source and the fuel tank. McCollom further discloses a resilient seal surrounding the flow body of the adapter so as to lie between movable and stationary seal stops. A force-generating member is moved along the flow body to push the movable seal, bulging the seal outwardly towards and against the fuel mouth of the filler pipe.
The inventors herein have recognized potential issues with the aforementioned adaptor. For example, the adaptor of McCollom provides only a single seal between the fuel tank system and the leak detection test system. If the force-generating member does not install the seal correctly or securely, the visible vapor or vacuum provided during leak detection testing may escape and the leak detection test may be inaccurate. In another example, force-generating member of the adaptor of McCollum protrudes outwards from the vehicle's fuel mouth at a distance away from the fuel mouth. The outward protrusion of the adaptor may hinder the ability to run the leak detection test in certain types of vehicles, particularly in plug-in hybrid vehicles.
In one example, the issues described above may be addressed by an adaptor for a fuel tank of a vehicle, comprising a hollow shaft having a threaded top end, the hollow shaft inserted through a mouth of a filler pipe of the fuel tank, a gasket arranged on the hollow shaft, wherein a position of the rubber gasket may be adjustable only along a longitudinal length of the hollow shaft, and an end cylinder having an elastic piece threaded on the hollow shaft configured to create a seal on a fuel mouth. In this way, an airtight fluidic connection may be provided between a leak detection system and the fuel tank during EVAP testing, for example, to effectively and rapidly test the presence of leaks in a fuel system.
As one example, an elastic piece of the end cylinder may at least partially fit in an inner circumference of the fuel mouth, such that a projection of the adaptor out from the fuel mouth is reduced when the threaded top end of the hollow shaft receives a nozzle of the leak detection system. Further, the elastic piece of the end cylinder arranged within the inner circumference of the fuel mouth may create an airtight seal between the fuel mouth and the end cylinder. In this way, only a single flow path through the adaptor from the leak detection system to the fuel tank may be provided during leak detection testing.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.